M in the Demon Realm - a dark fantasy by Mark William Hammond

Emma is a young Asian waitress in New York City who discovers she is the last in a line of Demon Killers and Hell Gate Closers when local demons begin to hunt her and kill those around her. She must become a warrior to save herself, her adoptive parents, the city and the world. All she has to do is steal her legacy 20ft ribbon sword from the Metropolitan Museum, become the most deadly sword master on the planet and put hell back in the box. She's a NY waitress but this may be asking too much.